12a Disassembly Question?
 

ok, so im trying to tear down the "spare" motor i got with my car, but im having a bit of a time with the front bolt. my buddy's impact that is rated to 750 ft-lbs wouldnt budge it... actually we tried spinning it both ways, nothing.

the plan now is a locked flywheel and a really long pipe... should i find someone with a stronger impact? should i heat it?

i guess its a dumb question, but is it a regular right-handed thread? i would think that it is, but i dont want to tighten it trying to loosen it. haha

It is a normal right hand thread.

The front pulley bolt is a royal bitch to get off. Most people put a thread locker on there, some put too much or use a permanent type. Try heating it with a Mapp torch until nice and hot. Or a propane torch if that's all you have will take a long time to heat it.

I had one motor where the shop put a green threadlocker on there and it was horrible to get off. I ended up locking the flywheel and using a I shit you not 6 foot cheater pipe over my breaker bar.

Lefty loosy on the front 19mm bolt. You have to lock the flywheel to have any chance at front bolt removal. Also heat it up with a MAPP gas torch. Propane can work. You're supposed to burn off the locktite that some engines had. Others come off just fine at 70 to 90 foot pounds of tightness which is factory spec even with supposed loctite. It's a gamble - some engines are easy and others make you want to grab your BFH. Usually the ones assembled by idiots - you know who you are.

Speaking of my BFH, I had a couple of insane FD engines. These normally are tightened to 200 foot pounds. Yeah that's what I said. But they still can come off with a normal impact, but not these two. I tried everything I could think of. No budge. So I grabbed an old craftsman 3/4" wrench, made sure the flywheel was locked, and with the bolt basically still glowing, I'd beat on the wrench like an abusive character is a William S Burroughs... anyway it would move a tiny bit with each hit until you swear the shaft was twisting, and only then would it start to show signs of loosening up. I might have bent the shaft on those two so I picked up a set of v-blocks to check for run out.

lol i have access to some very long cheater pipe, but i figured that impact would do it... i have seen it take off bolts that have broken breaker bars before, literally.

my crappy lil electric craftsman impact took off the flywheel nut but wouldnt touch anything else lol

ok, this may be another dumb question but should i heat it straight on, or behind the pulley, or both?

Straight on. Take the pulley off the hub first (four 10mm head bolts).

I just opened up two 12a's this week. I got a IR 3/4 drive impact turned on 5 and it's pop pop pop popp vrrooom ... Never had a problem with either of them. I tap the bolt with a hammer a couple times and it came right off. Hell even the 54mm flywheel nut acted like it wasn't even there. But I've used this gun on a Mack trucks pinion bolts and they're at 800-900 lbs.

I've never needed an impact wrench for the flywheel nut or the front pulley bolt. But if you don't immobilize the flywheel, you're just wasting time - - the impact simply transfers right thru to the shaft.

im gonna try and tackle it again here in a couple days lol.. got too many projects goin on all at the same time haha

Did you guys use a special tool to lock the flywheel? I will be tearing down in about 3 hours (if we get out of work early today).

There are a few locking tools out there from places like Mazdatrix.

The one I use is essentially a 3-foot piece of 1.5" x 0.25" rolled steel bar stock with two holes drilled in it, allowing it to be bolted to the flywheel at a tangent. This is then braced on the floor or a suitable strong rest that the engine is on.

Pictures of the process:
Removing flywheel nut:
Attachment 677254

Installing flywheel nut:
Attachment 677255

Removing or Installing front pulley bolt:
Attachment 677256

I use an earlier version of one of these.
http://www.mazdatrix.com/pictures/to...rbostopper.jpg

Those are some awesome pics DD, I will look into making something along those lines. Not much can go wrong with flat steel.

In the TII engine I've been working on I went out and bought one of these from Autozone:
http://www.northerntool.com/images/p...s/15233_lg.jpg
and held the front pulley tight with it resting on the water pump pulley and she came off without much hassle.

Worked on two engines today. Both needed some sort of stock flywheel or a rear CW and an aftermarket flywheel.
https://www.rx7club.com/attachment.p...1&d=1364626869

As mentioned earlier, I have the early version of what Mazdatrix sells. It's just a flywheel starter ring gear they chopped and welded a couple steel tubes to, then had it plated.
https://www.rx7club.com/attachment.p...1&d=1364626520

It's a little off but works well enough.
https://www.rx7club.com/attachment.p...1&d=1364626520

And not to leave the rear CW folks out, I came up with an angle iron that works perfectly for these.
https://www.rx7club.com/attachment.p...1&d=1364626520

i believe it was on here i saw where someone used the part of an engine stand that actually bolts to the motor to lock a flywheel, i will probably be trying that, ill snap some pics and post em up

Actually bought mine (and the humungous nut wrench) from Mazdatrix years back, but so long as you can drill heavy steel no reason why you can't fab one.

Currently out on loan to 80's Old School, or I'd get some measurements for you.

they and/or racing beat still sell em! RX7 1975-1985: Flywheels: Flywheel Nut Wrench Tool -

RX7 1975-1985: Flywheels: Flywheel Stopper Bar Tool -

Made by RB, sold via MTrix; not uncommon. Cheap compared to an impact socket that size.